Hot-air furnace



A. L. SMITH.

HOT AIR FURNACE. APPLICATION FILED FEB. 11, IQZL-RENEWED FEB. 14,1922.

Patentedsept. 12, 1922.

' tot ddmizLSi/a'ik attozncg Patented Sept. 12, 1922.

warren stares ADAM I4. sierra, or rounesro'wr, care.

.i HOT-AIR FURNACE.

Application filed. February 11, 1921, Serial no.' i44,167. nenewe'aFebruary 14, 1922. Serial No. 536,537.

To all whom it may concern Be it known that I, ADAM L. SMITH, a citizenof the United States,- residing at Youngstown, in the county of Mahoningand State of Ohio, have invented certain new and useful Improvements ina Hot-Air Furnace, of which the following is a speci fication.

This invention relates to improvements in hot air furnaces, and hasparticular reference to hot air furnaces, utilizingg'as as a heatingmedium.

The principal objects of the invention are; to provide an improvedfurnace structure wherein cold air is caused to pass through a series ofheated tubes forming a part of heating chambers without becomingsaturated with gases and other products of coinbustion; to provide afurnace I structure wherein a maximum heating efliciency is ob tained,and to provide an improved burner wherein both air and gas are utilizedas fuel.

For the purpose of illustrating this invention there is shown in theaccompanying drawing one form thereof which is at present preferred,since the same has been found in practice to give satisfactory andreliable re sults, although it is to be understood that the variousinstrumentalities of'which the invention consists can be variouslyarranged and organized and that the invention is not limited to theprecise arrangement and organization of these instrumentalities as herein shown and described.

In the drawing: l

Figure 1 is a sectional side elevation of the invention.

Figure 2 is top plan View of the same, partly broken away to show thedisposition of the air circulating tubes.

Like characters of reference indicate like or similar parts throughoutthe several views, in which:

A designates the outer casing 'of a furnace which rests upon a suitableheat resisting foundation B and has communicating with the lower portionthereof a cold air intake conduit 1, while formed in the top wall 2 ofthe furnace are hot air outlet openings 3 about which are formed annularflanges 4; for receiving hot air pipes (not shown).

Arranged within the furnace casing A, and enveloped thereby, but spacedsome dis tance from the walls thereof is a heating chamber C, throughthe lower portion of which extends an air intake conduit 5 whichcommunicates with the casing i of a heating element generally designatedby D. Carried within the intake conduit 5 is a fuel supply pipe' 7 whichhas a vertically extending branch coupled to its end upon which iscarried a pin pointburn'er 8. Both the branch so that upon lighting thecombustible mixture of gas and air very hot flames of the properintensity and size will result. H

Extending from a water reservoir or tank (not shown) through the coldair intake 1 of the furnace into the heating chamber G is a water supplypipe 13 which communicates through a vertical pipe section 14 with thecoils 15 of a water heater E arranged in the heating chamber C above theheating element D. The upper coil of the water heater Eis extended toform a return pipe 16 to the reservoir and it is pointed out that inaddition to providing hot water whenthe furnace is operated, the coils15 form babies for distributing the heated air arising from the burner,which otherwise would be of greatest intensity at the top of thechamber.

Arranged about the heating chamber C adj acent the top 17 thereof is asupplementary air heating chamber 18through which extend a plurality ofair pipes 19 to permit the passage of cold air therethrough, andcommunicating with the chamber 18 through the conduits 20 is a primaryair heating chamber F which is arranged above the chamber C and extendsto a point adjacent but spaced from the side walls of the furnace asillustrated in Figure 1. The primary air heating chamber F also hasaplurality of air pipes designated by 21 arranged therein so that thecold air coming in through the inlet 1 will not only circulate aroundthe heating chamber C but through and about the air-heating chambers 18and F consequently ensuring maximum efficiency of the heating system.The primary heating chamber F is directly connected through the pipes 22with the chamber C so that the heated air passing from the chamber Cthereto will also pass downwardly to the chamber 18 and from thence outthrough the stack 23 connected, as illustrated with the chamber 18.

In order to insure proper distribution of incoming air a foraminatedplate 24 is arranged between the wall of the chamber C and the wall ofthe furnace casing A above the inlet 1 so that the incoming air willcirculate around and through the chambers as above described.

If desirable the casing A may be protected by some heat resistingcovering such as asbestos or fire brick (not shown), and attention isparticularly called to the fact that none of the obnoxious products ofcombustion such as gases and the like come into contact with the heatedair, thereby eliminating the most undesirable feature of hot air heatingsystems.

Attention is also called to the fact that expansion and contraction ofthe tubes,

heater E will be heated and a circulation will take place. The flamesarising from the heating element strike the coils of the hot waterheater, and the heated air issuing therefrom also strikes the same, bothwill be distributed to uniformlyheat the heating chamber C. The heatedair in the chamber C will pass through the conduits 22 to the primaryheating element E and from thence will pass downwardly to the secondaryheating element 18 and outwardly through the stack 23. The cold aircoming in through the inlet 1 will pass upwardly through the pipes 19 inthe secondary heating element and through the pipes 21 of the primaryheating element and outwardly through the outlet openings 3, in themeantime however messes a complete circulation of the incoming cold airwill take place around the outside of the ieating chambers in the mannerabove described in detail'thus effecting a maximum efiiciency of theheating system, Attention is called to the fact that none of theproducts of combustion come into contact with the heated air, I

From the foregoing description taken in connection with the accompanyingdrawing it is thought that a clear and comprehensive understanding ofthe construction, operation, and advantages of the invention may be had,but while I have shown and described the device as embodying a specificstructure, I desire it to be understood that such changes may be made insaid structure, as do not depart from the spirit and scope oftheinvention as: claimed.

hat I claim is: i

In a furnace of the class described, a supporting base, a closed casingmounted on said base, a cold air supply conduit opening into the lowerportion of said casing through one side wall thereof and hot air outletsin the top of said casing, a main heating chamber within the casing withthe walls thereof spaced from the casing walls, heating means insaidchamber, an auxiliary air heating chamber arranged above said mainheating chamber and extending adjacent to and spaced from said casingwalls, pipes connecting said main and auxiliary heating chambers, asupplementary air heating chamber surrounding said main chamber a pointbelow the auxiliary chamber and having a plurality of cold air pipesextending therethrough, pipes connecting said auxiliary and supplementalheating chambers, and an exhaust pipeleading from the bottom of saidsupplemental chamber In testimony whereof, I aflix my signature hereto.

ADAM SMITH.

